FAQ

Does this replace the official MCP SDK? No. The SDK owns transport (stdio/SSE, protocol messages). This package owns the testing layer.

Does it work without Vitest? Yes — plain async functions, zero runtime deps. Works with Jest and node:test.

How do I import from CommonJS?const { createMockServer } = require('mcp-works'); — dual ESM+CJS, verified by attw and CI smoke test.

How do I catch guard errors? All errors are McpWorksError with .code: TOOL_DENIED, TIMEOUT, OUTPUT_TOO_LARGE, ABORTED, INVALID_TOOL. Switch on code for retries.